Field of the Invention
The present invention relates to an ophthalmologic apparatus, a fundus camera for photographing and observing an eye to be inspected and a control method therefor.
Description of the Related Art
An ophthalmologic apparatus, particularly, a fundus camera for photographing and observing an eye to be inspected needs to align an ophthalmic part with a predetermined position with respect to the eye to be inspected. Conventionally, there is known an ophthalmologic apparatus having a slide mechanism that mechanically moves, through manual operation of a joystick by an inspector, a movable part on which the ophthalmic part is placed in a horizontal direction with respect to a fixing part. Further, there is known an ophthalmologic apparatus wherein a drive mechanism capable of moving the ophthalmic part in forward-backward, left-right and up-down directions is provided on such a movable part so as to enable automatic alignment (see Japanese Patent Application Laid-Open No. 2009-201981).
A so-called auto alignment where alignment is automatically performed can achieve alignment in a shorter time than manual alignment. However, when an eye to be inspected to be photographed is large in involuntary eye movement, the ophthalmic part moved by the drive mechanism may fail to follow the movement of the eye to be inspected. In such a case, the eye to be inspected may fail to be photographed properly in the auto alignment. Further, when the eye to be inspected is to diseased eye that cannot be photographed properly even when alignment is made on a pupil center, minute operation is required for the alignment. In such a case, manual alignment using an electric alignment operation member (electric joystick, trackball, etc.) has poor operability, which may take a lot of time and trouble to achieve alignment.
As a counter measure, an operation sequence can be considered, in which alignment up to the pupil center for which minute operation is not required is performed with the auto alignment and, thereafter, minute manual alignment using a mechanical slide mechanism and an alignment operation member is performed if minute operation is required. Therefore, a configuration in which the above operation sequence can be executed is desired.
For execution of the above operation sequence in a conventional ophthalmologic apparatus, a two-stage movable part configuration in which an electric movable part is placed on a mechanical movable part is required. However, in such a two-stage configuration, the electric movable part may be positioned close to an eye to inspected side (left or right eye). In this state, it is necessary to take into consideration that a gravity center or ophthalmic part is offset with respect to the mechanical movable part.